Cutaneous Vasculitis

Vasculitis is a term referring to inflammation of blood vessels; these may be arteries, veins, or both, and can affect any part of the body.

When vasculitis affects small or medium-sized blood vessels in the skin, it is known as cutaneous vasculitis. Occasionally cutaneous vasculitis can be a sign of inflammation occurring in other organs (a systemic vasculitis), and further investigation may be required for a full diagnosis.

Cutaneous vasculitis may be caused by an infection, medications, autoimmune diseases, malignancy (cancer), or blood disorders. In about half of the cases, no cause is found. 

The triggers can induce the increased activity of the immune system (the body’s defense system), with increased production of inflammatory mediators, which cause damage to blood vessel walls. Fluid may also leak from the blood vessels into the surrounding tissues that can result in swelling, especially of the lower legs.

Infections: Vasculitis can occur 7-10 days after a viral or bacterial illness. 

Autoimmune conditions: Vasculitis may occur in patients with autoimmune diseases (where the immune system reacts against patients own tissues) such as rheumatoid arthritis, lupus, and inflammatory bowel disease.

Medications: More than 100 drugs have been associated with drug-induced vasculitis. These include antibiotics, anticonvulsants, diuretics, and non-steroidal anti-inflammatory agents. Any new medicines taken will be the initial suspect of causing a vasculitic rash.

Malignancy or Haematological (blood) disorders: Cancers may be associated with increased thickening of the blood or development of antibodies, which can cause blood vessel damage. Abnormalities of the red or white blood cells can also lead to vasculitis.

The most common type of cutaneous vasculitis is cutaneous small vessel vasculitis (CSVV).

This usually appears as non-blanching (the color does not disappear when pressed) or bruise-like marks on the skin, some of which may be raised lumps.

These marks are typically small but may measure between 1 millimeter to several centimeters as rarely, pustules, blisters, and wheals that heal with darker skin coloration.

These often cause no symptoms but can sometimes cause pain, burning, and itching. The ankles and lower legs, as well as pressure points on the knees, back of the foot and lower legs, are most frequently affected. Pressure points are found near joints and junctures and are specifically sensitive areas on the body.

If medium-sized vessels in the skin are affected, a network-like skin discoloration, ulceration, or larger raised lesions may be seen.

Other symptoms to be aware of, which may suggest the involvement of organs other than the skin include: • Fever • Nausea and vomiting • Blood in urine • Joint and muscle aches • Muscle weakness • Tingling or numbness in the hands and feet  • Chest pain • Breathlessness or cough • Abdominal pain • Blood in the feces

The diagnosis can often be made based on the appearance of the skin. 1. A skin biopsy (tissue sample) usually confirms the diagnosis in classic cases, but this is not always required. 2. Blood tests are often carried out to check for the presence of infection, autoimmune, and inflammatory conditions as well as blood abnormalities. 3. A urine sample, blood pressure check, and blood tests are useful to exclude the involvement of other organs. 4. Very rarely, scans may be needed to check for vasculitis in other organs.

Any underlying causes should be treated. For example, any possible medication reactions should be stopped (but only after advice by a doctor), and underlying infection should be treated. Otherwise,

• Leg elevation 
• Adequate rest 
• Analgesics 
• Antihistamines
• Non-steroidal anti-inflammatory drugs (except if there is kidney involvement)
• Steroid creams and ointments applied to the skin
• Dressings may be required if the skin is ulcerated, and the episode of vasculitis is prolonged, severe, or leading to ulceration.

• Colchicine
• Dapsone 
• Oral corticosteroids

In patients with severe or systemic disease, treatment with other medication which suppresses or modulate change to adjust the immune system, including immunotherapy, may be required. 

The outlook is good, with a full recovery in 90% of cases (providing only the skin is involved). The rash may recur at intervals for some time after the initial episode. Even after successful treatment, the areas affected by vasculitis can become more pigmented (brown or black) as compared to non-affected skin. This discoloration usually takes months to fade to normal.